Extension plans for a single-family house from 2 to 4 children's rooms. Ideas welcome!

By the way, I like the open plan living area: large dining area, a family corner there, and behind that the chill-out zone. Where do you have the technology? And where do you do the laundry? Everything in the utility room including the freezer??? Do you actually have a lot of guests? Do you need a room? Or an office? I would leave the cloakroom as an enclosed cloakroom/dressing room. Without an outside door. Later, when the children are tidier again and take their jackets independently to their wardrobes in their rooms, it will be a nice multipurpose room. I can imagine that in a few years the older sister will/wants to move to the ground floor. But I also rather see a parents’ area downstairs. For a granny flat (later) there is the possibility to still connect “living room and office new” “now” and later set up a bathroom in the cloakroom. Or later retrofit the entrance from the carport to the cloakroom and close the staircase area to the main entrance, then the ground floor uses the main entrance with everything without stairs and cloakroom. In both cases, I see the access to the “guest” (later bedroom) in the new living room.

In the meantime, quite a bit has changed, and the current proposal from the architect is to do without the partition wall. Consequently, we will of course remove the insulation.

I recently forgot to mention this: on the one hand, I can see in the plans that the existing gable wall, which is now becoming an interior wall, is retained at its unchanged thickness – that is, with no apparent removal of the external thermal insulation composite system (ETICS); and on the other hand, one apparently notices a different wall construction for the extension. Why does the architect not remain "homogeneous" with the wall construction in such a young existing building?